From 1c4f0dd95d9bac9e2b87a627b563bc5d9fb34555 Mon Sep 17 00:00:00 2001 From: Yasuyuki Kozakai Date: Sun, 22 Jul 2007 18:07:48 +0200 Subject: [PATCH] [NETFILTER]: nf_conntrack: don't track locally generated special ICMP error The conntrack assigned to locally generated ICMP error is usually the one assigned to the original packet which has caused the error. But if the original packet is handled as invalid by nf_conntrack, no conntrack is assigned to the original packet. Then nf_ct_attach() cannot assign any conntrack to the ICMP error packet. In that case the current nf_conntrack_icmp assigns appropriate conntrack to it. But the current code mistakes the direction of the packet. As a result, NAT code mistakes the address to be mangled. To fix the bug, this changes nf_conntrack_icmp not to assign conntrack to such ICMP error. Actually no address is necessary to be mangled in this case. Spotted by Jordan Russell. Upstream commit ID: 130e7a83d7ec8c5c673225e0fa8ea37b1ed507a5 Signed-off-by: Yasuyuki Kozakai Signed-off-by: Patrick McHardy Signed-off-by: Adrian Bunk --- net/ipv4/netfilter/nf_conntrack_proto_icmp.c | 22 +++++--------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c index 52dc175be39a..bccca5df8852 100644 --- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c +++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c @@ -193,25 +193,13 @@ icmp_error_message(struct sk_buff *skb, h = nf_conntrack_find_get(&innertuple, NULL); if (!h) { - /* Locally generated ICMPs will match inverted if they - haven't been SNAT'ed yet */ - /* FIXME: NAT code has to handle half-done double NAT --RR */ - if (hooknum == NF_IP_LOCAL_OUT) - h = nf_conntrack_find_get(&origtuple, NULL); - - if (!h) { - DEBUGP("icmp_error_message: no match\n"); - return -NF_ACCEPT; - } - - /* Reverse direction from that found */ - if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) - *ctinfo += IP_CT_IS_REPLY; - } else { - if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) - *ctinfo += IP_CT_IS_REPLY; + DEBUGP("icmp_error_message: no match\n"); + return -NF_ACCEPT; } + if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) + *ctinfo += IP_CT_IS_REPLY; + /* Update skb to refer to this connection */ skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general; skb->nfctinfo = *ctinfo; -- 2.39.5